Mask pack

ABSTRACT

A mask pack impregnated with a liquid cosmetic preparation, being applied to a human skin surface, in particular a facial skin surface. The mask pack includes a nonwoven fabric layer and a nanofiber layer including a hydrophilic polymer, wherein said nanofiber layer is bonded to the nonwoven fabric layer.

FIELD OF THE INVENTION

The present invention relates to a mask pack impregnated with a liquid cosmetic preparation, being applied to a human skin surface, in particular a facial skin surface.

BACKGROUND OF THE INVENTION

Mask packs are generally used in the field of cosmetics, in particular to protect the skin from external stimuli, dryness etc. Conventionally, nonwoven mask packs in which nonwoven fabrics are impregnated with a liquid cosmetic preparation have been used for application to facial skin surfaces.

FIG. 1 shows a conventional nonwoven mask pack.

However, such nonwoven mask packs are thick (about 15 to 50 μm) and have a small surface area per volume, and thus, can be easily detached from facial skin surfaces even under slight facial movement. Furthermore, nonwoven mask packs exhibit a poor long-lasting effect of a liquid cosmetic preparation after attachment to facial skin surfaces.

In this regard, nanofiber-coated nonwoven mask packs have been suggested. Nanofibers have a larger surface area and a smaller thickness (less than about 1 μm) than nonwoven fabric fibers. Thus, nanofiber-coated nonwoven mask packs can exhibit significantly improved skin adhesion, as compared to conventional nonwoven mask packs. For example, Japanese Patent Laid-open Publication No. 2007-70347 discloses a nonwoven fabric for skin adhesion and a facial mask pack. The literature discloses a nonwoven fabric laminate for skin adhesion including a nanofiber layer used as an adhesive surface to the skin and a nonwoven fabric layer. However, such nanofiber-coated nonwoven mask packs depend on only electrostatic force for the adhesion between nanofibers and nonwoven fabrics, and thus, they may easily undergo layer separation (nanofiber delamination) when impregnated with a liquid cosmetic preparation.

Therefore, it is necessary to develop mask packs improved in terms of skin adhesion and nanofiber delamination.

SUMMARY

The object of the present invention is to provide a mask pack improved in terms of skin adhesion and nanofiber delamination.

In order to achieve the object above, the present invention provides a mask pack including: a nonwoven fabric layer and a nanofiber layer including a hydrophilic polymer, wherein said nanofiber layer is bonded to the nonwoven fabric layer.

The mask pack can exhibit good impregnation with a liquid cosmetic preparation and good skin adhesion due to a hydrophilic nanofiber layer, and it can significantly improve a nanofiber delamination phenomenon due to a intimate bond between the nonwoven fabric layer and the nanofiber layer, in particular, by a use of an adhesive layer when impregnated with a liquid cosmetic preparation.

BRIEF DESCRIPTION OF THE DRAWINGS

The above and other features and advantages of the present invention will become more apparent by describing in detail exemplary embodiments thereof with reference to the attached drawings in which:

FIG. 1 shows a conventional nonwoven mask pack.

FIG. 2 illustrates a mask pack according to one embodiment of the present invention.

FIGS. 3A through 3C illustrate a method of manufacturing a nanofiber-coated mask pack according to an embodiment of the present invention. FIG. 3A illustrates the formation of a nonwoven fabric layer, FIG. 3B illustrates the formation of an adhesive layer on the nonwoven fabric layer, and FIG. 3C illustrates the formation of a nanofiber layer on the adhesive-coated nonwoven fabric layer.

Hereinafter, the present invention will be described in more detail.

DETAILED DESCRIPTION

The present mask pack includes a nonwoven fabric layer and a nanofiber layer including a hydrophilic polymer, wherein said nanofiber layer is bonded to the nonwoven fabric layer.

The present inventors found that when forming a nanofiber layer on a rayon-PET spunlace nonwoven fabric widely used in the field of mask packs to improve skin adhesion, the resultant mask pack easily underwent nanofiber delamination when impregnated with a liquid cosmetic preparation. While searching for a solution to prevent such a nanofiber delamination phenomenon, the present inventors found that when forming a bond between a nonwoven fabric layer and a nanofiber layer, for example, by forming an adhesive layer on a nonwoven fabric followed by nanofiber coating, the resultant mask pack exhibited significantly reduced nanofiber delamination and enhanced skin adhesion without skin irritation.

FIG. 2 illustrates a mask pack according to one embodiment of the present invention. In FIG. 2, reference numeral 1 represents a nonwoven fabric layer, reference numeral 2 represents an adhesive layer, and reference numeral 3 represents a nanofiber layer. These layers will be described in detail hereinafter.

Nonwoven Fabric Layer

In the present invention, the nonwoven fabric layer is a basic sheet of the mask pack impregnated with a liquid cosmetic preparation. The nonwoven fabric layer is not particularly limited provided that it is made of a nonwoven fabric commonly used in the art. A nonwoven fabric including a hydrophilic fiber is preferred in order to facilitate the impregnation of a liquid cosmetic preparation. The hydrophilic fiber may be at least one selected from rayon, cotton, pulp, nylon, cellulose, etc.

The nonwoven fabric layer may also include a polymer such as polyester (PET) to ensure easy handling property, processibility, etc. A composite nonwoven fabric layer composed of a hydrophilic fiber and a polymer may be a nonwoven fabric layer including rayon and PET. In this case, the weight ratio of rayon and PET may range from 5:5 to 9:1, more preferably from 7:3 to 8:2.

The nonwoven fabric layer may be a meltblown nonwoven fabric, a spunbond nonwoven fabric, a spunlace nonwoven fabric, etc. in view of a nonwoven fabric fabrication process, but the present invention is not limited thereto.

The term “nonwoven fabric” as used herein is a web including a plurality of fibers oriented randomly. Here, the fibers may be staple fibers or continuous filaments.

The content of the nonwoven fabric layer may range from 96.5 to 99 wt %, based on the total weight of the mask pack. The thickness of the nonwoven fabric layer is not particularly limited, but may range from 0.30 to 0.40 mm. The mass per unit area of the nonwoven fabric layer is not particularly limited, but may range from 40 to 60 gsm.

Nanofiber Layer

In the present invention, the nanofiber layer is used as an adhesive surface to the skin. The nonwoven fabric layer is present on an opposite surface of the mask pack to the adhesive surface to the skin, if any, with the adhesive layer being sandwiched therebetween.

The nanofiber layer can exhibit excellent skin adhesion due to easy entry of nanofibers into the pores of the skin, and can significantly enhance the retention of a liquid cosmetic preparation due to nano-sized fibers.

The nanofiber layer includes a hydrophilic polymer since it is used as an adhesive surface to the skin. The hydrophilic polymer that can be used herein may be at least one selected from polyacrylonitrile (PAN), hydrophilic polyurethane (PU), polyvinylalcohol (PVA), nylon (Nylon 6), hydrophilic polyvinylidenefluoride (PVDF), hydrophilic polyethersulfone (PES), polyetherimide (PEI), etc. Preferably, the hydrophilic polymer is polyacrylonitrile (PAN).

The nanofiber layer may further include thermoplastic polyurethane (TPU) to enhance softness upon adhesion to the skin and to prevent damage to the nanofiber layer due to an external friction or contact, e.g., scratch or crack. The polyurethane polymer may be a polymer modified to have a hydrophilic property. The polyurethane polymer may also have a hydrophobic property. Here, the weight ratio of polyacrylonitrile and polyurethane may range from 6:4 to 9:1.

The content of the nanofiber layer may range from 0.6 to 3 wt %, based on the total weight of the mask pack, and the mass per unit area of the nanofiber layer may range from 0.4 to 2 gsm in view of air permeability. In order to ensure better skin adhesion and good permeation of a liquid cosmetic preparation into the skin during the use of the mask pack, the pore size of the nanofiber layer may range from 0.8 to 3 μm, and the diameter of a single nanofiber may range from 100 to 300 nm. The thickness of the nanofiber layer is not particularly limited, but may range from 0.5 to 2 μm.

The nanofiber layer may be in the form of nanofibers being dispersed or agglomerated. Preferably, the nanofiber layer may be in the form of nanofibers being bound together.

In order for nanofibers to be bound together, the present nanofiber layer may further include hot-melt polyurethane (hot-melt PU). Hot-melt PU is an adhesive widely known in the art, including a thermoplastic polyurethane resin as a major component, and is a 100% solid adhesive without water and organic solvent. Hot-melt PU may be composed of a polyurethane resin only, but may further include wax, a tackifying resin, a plasticizer, etc., similarly to a general hot-met adhesive. Hot-melt PU can facilitate a fiber-fiber binding of the nanofiber layer, and furthermore, can assist an adhesion between the nanofiber layer and the nonwoven fabric layer. The hot-melt PU may be used in an amount of 5 to 15 wt %, based on the total weight of a composition forming the nanofiber layer.

In addition to the above components, the nanofiber layer may include an additive (e.g., a pigment) commonly used in the art, in an amount not adversely affecting the effects of the present invention, if necessary.

Bond Between the Nonwoven Fabric Layer and the Nanofiber Layer

In the present invention, the nanofiber layer is bonded to the nonwoven fabric layer. A bond between the nonwoven fabric layer and the nanofiber layer may be made by using one or more selected from the group consisting of an adhesive layer, a fusible film, heat or ultrasonic waves. For example, a nanofiber layer obtained by electrospinning or the like, may be adhered onto a nonwoven fabric layer by means of an adhesive, or alternatively, nanofibers may be electrospun onto an adhesive-coated nonwoven fabric layer.

The mask of the present invention may comprise at least one additional layer interposed between the nonwoven fabric layer and the nanofiber layer, which may be a bonding layer. At least one adhesive may be used as the bonding layer.

The adhesive layer that can be used herein may be made of an acrylic adhesive, a polyurethane adhesive, a polyester adhesive, a silicone adhesive or a combination thereof. Use of an acrylic adhesive, a polyurethane adhesive, and a polyester adhesive is preferable.

The adhesive may be used in a minimal amount capable of preventing nanofiber delamination without skin irritation. Generally, the content of the adhesive layer may range from 0.05 to 0.5 wt %, based on the total weight of the mask pack.

The adhesive layer may be formed on the nonwoven fabric layer using a method commonly known in the art, for example, a coating process, an evaporation (deposition) process, etc.

A nanofiber-coated nonwoven fabric is subjected to post-processing (a calendering process) commonly known in the art to prepare a mask pack of the present invention.

FIGS. 3A through 3C illustrate a method of manufacturing a nanofiber-coated mask pack according to one embodiment of the present invention. Referring to FIG. 3A, a nonwoven fabric layer 1 is first formed. Then, an adhesive is coated on the nonwoven fabric layer 1 to form an adhesive layer 2, as shown in FIG. 3B, and nanofibers are electrospun onto the nonwoven fabric layer 1 coated with the adhesive layer 2 to form a nanofiber layer 3, as shown in FIG. 3C, to complete the present mask pack.

The present mask pack may be impregnated with a liquid cosmetic preparation. A liquid cosmetic preparation impregnated in the present mask pack may contain a moisturizing ingredient, a cleansing ingredient, a whitening ingredient, a UV blocking ingredient, or the like, as an effective ingredient, but the present invention is not limited thereto. The liquid cosmetic preparation may also contain any ingredient expected to perform a special action on the skin.

The amount of the liquid cosmetic preparation impregnated in the mask pack is appropriately determined according to the properties (in particular, the retention property of the cosmetic preparation) of the mask pack. Preferably, the liquid cosmetic preparation may be impregnated in an amount ensuring the supply of a sufficient amount of effective ingredient(s) to the skin and the minimized occurrence of any inconvenience (e.g., liquid dribbling) upon use.

The presentive mask pack may be used for other applications as well as for facial application. For example, the presentive mask pack impregnated with a liquid cosmetic preparation containing moisturizing ingredient(s) may be applied to the neck, elbows or heels.

Hereinafter, the present invention will be described more specifically with reference to the following working examples. However, the following working examples are only for illustrative purposes and are not intended to limit the scope of the invention.

EXAMPLES Example 1

First, a rayon-PET spunlace (60 gsm) including viscose rayon and PET (weight ratio 8:2) (Namyang Textile Co., Ltd.) was prepared as nonwoven fabric.

A polyurethane adhesive (0.3 g) was coated on the nonwoven fabric to form a polyurethane adhesive-coated rayon-PET spunlace nonwoven fabric.

A solution of PAN (6.30 g), hydrophilic PU (3.15 g), hot-melt PU (1.04 g) and a pigment (0.01 g) in dimethylacetamide (89.5 g) was applied onto the adhesive-coated nonwoven fabric by an electrospinning process to thereby complete a nanofiber-coated nonwoven fabric. At this time, the mass per unit area of the nanofiber layer was adjusted to be 0.4, 0.8 or 1.1 gsm.

The nanofiber-coated nonwoven fabric was cut, and the resultant nonwoven fabric samples were folded twice and placed into cases for mask packs. A liquid cosmetic preparation (22 g, HongSam (C&Tech)) was then incorporated into the cases. The resultant packages were sealed and stored at room temperature for 3 days, 7 days and 15 days to prepare desired mask pack samples.

Example 2

Nowoven fabric samples obtained in the same procedure as in Example 1 except that the mass per unit area of nanofibers was 0.3 or 1.3 gsm were folded twice and placed into cases for mask packs. Then, a liquid cosmetic preparation (22 g, HongSam (C&Tech)) was then incorporated into the cases.

The resultant packages were sealed and stored at room temperature for 30 minutes to prepare desired mask pack samples.

Example 3

Nonwoven fabric samples obtained in the same procedure as in Example 1 were folded twice and placed into cases for mask packs. Then, a liquid cosmetic preparation (22 g, HongSam (C&Tech)) was then incorporated into the cases. The resultant packages were sealed and stored at room temperature for one day to prepare desired mask pack samples.

Comparative Example 1

Nonwoven fabric samples obtained in the same procedure as in Example 1 except that no polyurethane adhesive layer was formed were folded twice and placed into cases for mask packs. Then, a liquid cosmetic preparation (22 g, HongSam (C&Tech)) was then incorporated into the cases. The resultant packages were sealed to prepare mask pack samples.

Evaluation Example 1 Nanofiber Delamination Test

For the mask pack samples prepared in Example 1 and Comparative Example 1, the occurrence of nanofiber delamination was observed with the naked eye. The results are summarized in Table 1 below.

TABLE 1 Mass per unit area Nanofiber delamination Sample (gsm) of nanofibers 3 days 7 days 15 days Example 1 0.4   NO¹⁾ NO NO 0.8 NO NO NO 1.1 NO NO NO Comparative 0.4 Occurrence of delamination Example 1 after 20 minutes 0.8 Occurrence of delamination after 20 minutes 1.1 Occurrence of delamination after 20 minutes ¹⁾NO: not observed

As presented in Table 1, in the present mask packs, no delamination of nanofibers occurred even after 15 days. On the contrary, the mask packs with no polyurethane adhesive layer underwent nanofiber delamination after 20 minutes.

Evaluation Example 2 Skin Adhesion Test

The mask pack samples prepared in Example 2 were applied onto the skin surfaces of five persons for 30 minutes, and the degree of skin adhesion (peeling resistance) was evaluated. The conventional mask pack sample without nanofibers was used as control and evaluated. The results are summarized in Table 2 below.

-   -   X: poor     -   O: good     -   ⊚: excellent     -   (The above results are prepared based on an average of five         persons)

TABLE 2 Mass per unit area Sample (gsm) of nanofibers Skin adhesion Sample 1 0.3 ◯ Sample 2 1.3 ⊚ Control 0 X

From the results of Table 2, it can be seen that the present mask pack exhibits better skin adhesion than a conventional nonwoven mask pack.

Evaluation Example 3 Skin Irritation Test

The mask pack samples prepared in Example 3 were applied onto the skin surfaces of four persons for 30 minutes, and the presence or absence of skin irritation (e.g., itching, inflammation) was observed. The results are summarized in Table 3 below.

TABLE 3 Skin irritation Mass per unit Mass per unit Mass per unit area(0.4 gsm) area (0.8 gsm) area (1.1 gsm) Person of nanofibers of nanofibers of nanofibers Person 1 NO¹⁾ NO NO Person 2 NO NO NO Person 3 NO NO NO Person 4 NO NO NO ¹⁾NO: not observed

From the results of Table 3, it can be seen that the present mask pack is very safe to the human skin. 

What is claimed is:
 1. A mask pack comprising: a nonwoven fabric layer; and a nanofiber layer comprising a hydrophilic polymer; wherein said nanofiber layer is bonded to the nonwoven fabric layer.
 2. The mask pack of claim 1, wherein the bond between the nanofiber layer and the nonwoven fabric layer is made by using one or more selected from the group consisting of an adhesive layer, a fusible film, heat, and ultrasonic waves.
 3. The mask pack of claim 1, comprising at least one additional layer interposed between the nonwoven fabric layer and the nanofiber layer.
 4. The mask pack of claim 3, wherein said additional layer is a bonding layer.
 5. The mask pack of claim 4, wherein said bonding layer comprises at least one adhesive.
 6. The mask pack of claim 5, wherein said adhesive is selected from the group consisting of an acrylic adhesive, a polyurethane adhesive, a polyester adhesive, and a silicone adhesive.
 7. The mask pack of claim 1, wherein the nonwoven fabric layer comprises at least one hydrophilic fiber selected from the group consisting of rayon, cotton, pulp, nylon and cellulose.
 8. The mask pack of claim 1, wherein the nonwoven fabric layer comprises a rayon fiber and a polyester (PET) fiber.
 9. The mask pack of claim 8, wherein the weight ratio of the rayon fiber and the PET fiber of the nonwoven fabric layer ranges from 5:5 to 9:1.
 10. The mask pack of claim 1, wherein the hydrophilic polymer of the nanofiber layer is at least one selected from the group consisting of polyacrylonitrile (PAN), hydrophilic polyurethane (PU), polyvinylalcohol (PVA), nylon, hydrophilic polyvinylidenefluoride (PVDF), hydrophilic polyethersulfone (PES) and polyetherimide (PEI).
 11. The mask pack of claim 1, wherein the nanofiber layer further comprises thermoplastic polyurethane (TPU).
 12. The mask pack of claim 5, wherein the contents of the nonwoven fabric layer, the nanofiber layer and the adhesive layer are respectively a range from 96.5 to 99 wt %, 0.05 to 0.5 wt % and 0.6 to 3 wt %, based on the total weight of the mask pack.
 13. The mask pack of claim 1, wherein the nanofiber layer further comprises hot-melt polyurethane (hot-melt PU).
 14. The mask pack of claim 13, wherein the hot-melt PU is used in an amount of 5 to 15 wt %, based on the total weight of a composition forming the nanofiber layer.
 15. The mask pack of claim 1, further comprising a liquid cosmetic preparation. 